Why did Grant give Alice the gun? He seemed distracted..maybe he recognised the name of the man at the door? If he didn't, that's one rather major question answered...if he did...he gave the gun to Alice as the name of the man at the door was more of a pressing concern and it's about to get very messy indeed, because...

Spoiler

I'm starting to, sadly, fear that Letts isn't rabbit...I still really, really want him to be as that would mean Stephen Rea as killing machine...but if he is, expect one or more of the gang to be killed next week.